Mineral oil composition



'- Patented Mar. 20, 1945 2,371,854 MINERAL on. COMPOSITION Herschel G.Smith, Walling-ford, and Troy L. Cantrell, Lansdowne, Pa, assignors toGulf Oil Corporation, Pittsburgh, Pa., a corporation of Pennsylvania NoDrawing. Application September 27,1943,

' Serial N0. 504,057

' Claims.

This invention relates to lubricating oil com-= positions. Moreparticularly, the invention is concerned with mineral lubricating oilcompositions of a character adapted to protect ferrous and other metalsurfaces to which they ar applied, from rusting and other types ofcorrosion in addition to afiording lubrication of such surfaces.

Simple mineral oil films afford only a limited protection to metalsurfaces from rust and other types of corrosion, but do not afford anygreat protection under severe conditions of use. Many so-calledanti-rust lubricating oils have been proposed, consisting of mineraloils and added constituents intended to protect metallic surfaces fromrust, tarnishor 'corrosion. Most of them are of rather limitedapplicability, in that while they afford satisfactory protection to oneclass of metals, they may be ineifectivaor even deleterious, withanother class of metals.

These shortcomings of such mineral oils and oil compositions are seriousin manyv cases, particularly in cases wherein a plurality of metals mustbe simultaneously lubricated while exposed to corrosive conditions; forexample, in the case of copper-alloy bearings with steel shafting andthe case of electric motors where surfaces of both steel and copper areexposed to corrosive conditions. Moreover, many such oils show unduesensitivity to moisture and air and other substances to which they areexposed and lubricating films of such oils do not effectively protectthe metal against rusting or tarnishing when exposed to moisture and airor other corrosive atmospheres. It is also found that some compoundedoils which are eifective as regards preventing rust, are deficient inlubricating properties.

Among the objects of the present invention is the provision of ananti-corrosion lubricating oil composition, of good lubricatingproperties, adapted to protect steel from rusting while being of itselffree from tendency to corrode copper and other metallia surfaces, andbeing in itself relatively inert and unaffected by air and moisture.

These andother objects of v the invention are achieved by the provisionof a mineral oil composition, including as a rust inhibitor, thesubstantially neutral reaction products obtained by reacting primaryfatty amines containing from 8 'to 18 carbon atoms with acid phosphateesters of. .alkylated phenols containing at least one branched chainalkyl group, the said amines and acid phosphate esters being reacted inapproximately equimolecular: proportions under such conditions that thereaction product or mixture has a pH value between 5.5 and 7.5.

We have found that such improved oil compositions are very effective asanti-corrosion 1u-' bricants for metal surfaces in general. They formtightly adherent oil films on the metal, protecting the metal surfacesfrom moisture and air. In addition, the improved oil composition itselfis free from 'any tendency to attack. copper, steel and other metals byreaction therewith or otherwise. For instance, polished or highlyfinished steel surfaces protected byestablishing and main-- taining theimproved oil composition on the surfaces thereof remain brightindeflnitely and cop? per alloy bearings (which present a difficultproblem in protection from corrosion) are maintained in their highlyfinished condition even under unfavorable conditions of use. Further,copper, aluminum, zinc, silver, tin and their alloys are all effectivelyguarded against corrosion and are 'well lubricated by these improved oilcompositions containing our new rust inhibitors.

In general, various improved-lubricants, such as household lubricants,machine oils, gun oils,

turbine oils, slushing oils and the like are prepared, by selecting asuitable lubricating oil or base and dissolving the required amount ofthe above described reaction products in the oil.

In particular, the invention finds special utility.

in preparing improved-oil compositions of the so-called household type,useful for lubricating light mechanisms such as electric motors, guns,

ing oil to form a rust-preventive lubricant; Usually 0.5 per cent orless of the inhibitoris sumcient to impart to mineral lubricatingoilsadequate rust-inhibiting properties for metal articles exposed tomoisture and air, but as much as 25 per cent by weight on the oil issometimes incorporated to afford prolonged and complete protection fromrust underextremely severe conditions. Such highly concentratedcompositions,

That is, the inven-' still retain excellent lubricating and othercharacteristics in addition to affording practically complete rustprotection under extraordinary conditions.

The reaction products we employ are relatively stable compositions underordinary conditions. At room temperatures, some of them are heavyviscous oily liquids, while others are soft solids which melt to oilyliquids at slightly elevated temperatures. All of them are relativelynonvolatile. They are insolublein water and more or less waterrepellent. They are very resistant to hydrolysis. These reactionproducts or inhibitors are soluble in oils, both mineral and fatty oils.Their solubility varies somewhat with the particular oil. For instance,light paraflinic oils, such as employed in making household lubricants,etc., dissolve approximately 50.0 per cent by weight of these reactionproducts, forming stable solutions thereof. Naphthenic type mineral oilsdissolve somewhat larger amounts. In general, the solubility of thesereaction products or inhibitors is quite high in most oils.

These advantageous rust inhibitors can be readily prepared from primaryfatty amines containing from 8 to 18 carbon atoms and acid phosphateesters of alkylated phenols containing at least one branched chain alkylgroup, by reacting said amines and acid phosphate esters together inapproximately equimolecular ratios, as stated ante. In preparing ourrust inhibitors or reaction products, the reaction is controlled so asto produce substantially neutral reaction products or mixtures having apH value within the range 5.5 to 7.5 (as measured withquinhydronecalomel electrode assembly).

The primary fatty amines employed as one reactant are mono-alkyl amineshaving the following formula:

the said acid phosphate'esters. Further, they are readily available ascommercial materials. This advantageous class of primary fatty aminesmay be represented by the following formula:

where n is an even number between 6 and 16. ghis generic class includesthe following memers:

Mono-capryl amine, CH3(CH2) aCHzNHa Mono-lauryl amine, CH3 (CH2):oCH-Z'NH: Mono-myristyl amine, CH3(CH2)12CH2NH2 Mono-palmityl amine.CH3(CH2)14CH2NH2 Mono-stearyl amine, CH:(CH2)1sCH2NH2 Any of the aboveamines yield advantageous rust inhibitors when reacted with the saidacid phosphate esters as described ante.

That is, we sometimes prepare the rust inhibitors by reacting the acidphosphate ester with some particular one of these amines, but moreusually mixtures of fatty amines of this group are employed as theyafford a somewhat better product than if only one amine is used. One

' commercially available mixture, which we ordinarily employ, is theso-called coco amine" made in known ways by conversion of cocoanut Oilfat y acids into corresponding amines. Coco-amine contains a majoramount of mono-lauryl amine (the C1: amine) with minor amounts of itsadjacent homologues. The average molecular weight of cocoamine rangesbetween 200 and 210. A value within this range is considered as themolar weight in reacting cocoamine with the acid phosphate ester.

The other reactant, the acid phosphate esters. are di-esters ofortho-phosphoric acid and may be represented by the following genericformula:

wherein R, R. and R" represent hydrogen or an alkyl group, at least onebranched chain alkyl group being present. The acid phosphate diesters oftri-alkylated phenols containing a plurality of branched chain alkylgroups, such as tertiary and secondary butyl groups, are especiallyadvantageous in the practice of this invention, particularly those inwhich R is a tertiary butyl group and R and R' are alkyl groups selectedfrom the class consisting of methyl, secondary butyl and tertiary butylgroups, as more fully shown post.

These acid phosphate esters can be prepared by various methods fromalkylated phenols containing one or more branched chain alkyl groupsattached to the phenyl nucleus in the positions indicated ante. Inparticular, the acid phosphate di-esters of 4-tertiary-butyl phenol,2-tertiary-buty1-4-secondary butyl'phenol, 2,4-ditertiary-butyl phenol,2,6-ditertiary-butyl 4 secondary-butyl phenol, 2,4,6 tritertiary butylphenol, 2,6 ditertiarybutyl-4-methyl phenol and 4,6-ditertiary-butyl-2-methyl phenol are advantageous for the present purposes. For instance,as shown in the illustrative examples post, di-(2,4,6-tritertiary-butylphenyl) phosphate having the formula and di(2,4-ditertiary butyl phenyl)phosphate having the formula are advantageous in preparing our rustinhibiphosphate di-esters of alkylated phenol containing tertiary orsecondary 'alkyl groups are useful and advantageous in preparing ourrust inhibitors; those containing a plurality of such tertiary orsecondary alkyl groups being particularly advantageous for the presentpurposes. Such acid phosphate di-esters are readily soluble in mineraloils and have other properties rendering them advantageous for thepurposes of this invention.

As a class, these acid phosphate di-esters of alkylated phenolscontaining branched chain alkyl groups react readily with primary fattyamines. In general, the reaction is exothermic and is quite vigorous inmost cases. In preparing our rust inhibitors, the reaction temperatureis controlled by suitable means to secure smooth reaction and obtainaddition products of the amine and acid phosphate esters. In doing so,the temperature of the reaction mixture is controlled by cooling orheating as required; the temperature of the reaction mixture beingmaintained below 180 F., to avoid splitting out water from the mixture.The reaction temperature is usually maintained between l40and 170 F.during the larger portion of the reaction and within this rangeexcellent rust inhibitors are obtained; the pH value of the reactionproducts being adjusted in-the final stages of the reaction to withinthe desired range stated ante.

The following examples illustrate advantageous methods of preparingthese rust inhibitors:

Example 1.-To a suitable kettle equ pped with heating and cooling coilsand means for mechanical agitation there were added 210 pounds ofdodecyl amine, and then 536 pounds of di-(2,4,6-tritertiary-butyl-pheny!) phosphate were slowly added, the said acidphosphate being gradually added at such rate as to keep the temperatureof the reaction mixture below 180 F., whereby to avoid spl tting outwater from the mixture. After the addition of the acid phosphate, themixture had a pH of 3.0 and it was brought to the desired pH of 7.2 byadding 18 pounds of dodecyl amine and. stirring the final mixture forone hour. The substantially neutral reaction product so obtained was aheavy viscous oily liquid when cooled to room temperature. This reactionproduct or rust inhibitor was light amber red in color and had apleasant odor. It was sufiiciently soluble in mineral oils for thepresent purposes.

Similar viscous, oily rust inhibitors can be readily obtained havingother pH values within the range of 5.5 to 7.5, by controlled adjustmentof the pH during the last stages of the reaction. Likewise. our oilyrust inhibitors can be prepared from other primary fatty amines andother acid phosphate di-esters of alkylated phenols, as well as from theparticular amine and acid phosphate ester employed in Example 1. Thepreparation of another such advantageous rust inhibitor is illustratedin the following example.

Example 2.Here again, the reaction is carried out in a suitable kettleequipped with means for heating and cooling and for agitating themixture.

' Into such a kettle there were introduced 210, pounds of dodecyl amineand then 474 pounds of di-(2,4-ditertiary-butyl-phenyl) phosphate weregradually added with stirring. The reaction was 7 vigorous and quiteexothermic and the acid phosphate was added at such a gradual rate as tofacilaction mixture had a pH between 3 and 4 and the final adjustmentand control of the pH value was then effected. In doing so, 22 pounds ofthe amine were added and the mixture further heatrespectively, like theamines and acid phosphate itate maintaining the reaction temperaturebelow 180 F., the mixture being cooled ifdesired to maintain it belowthat temperature. In this way, the reaction temperature was maintainedbetween and F. during the larger portion of the reaction. After all theacid phosphate had been added, the mixture was warmed to facilitatecompletion of the reaction. At this stage, the reesters from which theywere prepared, are soluble in mineral oils. pare concentrated solutionsofthese rust inhibi-. tors in mineral oil by forming them in situ in theoil. In such processes, a fatty amine is first dissolved in the mineraloil and then the acid phosphate ester added, the mixture being stirredand maintained at the desired temperature until the reaction iscompleted and the mixture has a pH value within the specified range. Inpreparing such oil concentrates of our rust inhibitors sometimesadditional amine is added in the later stages to adjust the pH value asdesired. The concentrates or oil solutions of neutral reaction productsso obtained are useful addition agents to various types of lubricants.The preparation of such concentrates is illustrated in the followingexample.

Example 3.-817 pounds of light mineral lubricating oil having aviscosity of 100 seconds SUV at 100 F. were added to an iron vesselequipped with means for heating and cooling and agitation. The initialtemperature of the oil was 80 F. To

this oil were added 210 pounds of dodecyl amine which was thoroughlymixed with the oil by mechanical agitation and the final temperature ofthis mixture was 82 F. To the oil-amine mixture 58 pounds ofdi-(2,4,6-tritertiary-butylphenyl)phosphate were added over a period oftwo hours, during which time the mixture was agitated and thetemperature of the reaction mixture rose to 178 F. After stirring forone hour the pH of the mixture was 3.8. In order to increase this pHvalue to the desired range, 14- pounds of dodecyl amine were added-tothe mixture and stirred; the resultant mixture hada pH of 5.9. To securea final adjustment, 7 additional pounds of dodecyl amine were added tothe mixture which, after stirring for one hour and cooling to roomtemperature, had a pH of 7.2.

' The oily mixture prepared in this Example 3 can be regarded as a sortof concentrated stock solution which can be stored indefinitely andincorporated in lubricating oil as desired to prepare commercialanti-rust oils, etc.

In general, the rust inhibitors or reaction products prepared asdescribed ante, may be dissolved in various types of mineral oils andimproved anti-rust and non-corrosive oil compositions obtained which arecapable of inhibiting or retardingthe rusting or corrosion of variousmetals as described. The preparation of suchimproved mineral oilcompositions is illustrated in the fol- I lowing examples. 2

Example 4.-A household-type lubricant was prepared by dissolving 0.1 percent by weight of the rust inhibitor-obtained in Example 1 in a refinedoil. A

Example 5.Another household-type lubricant was prepared by dissolving0.1 per cent by weight Accordingly, we sometimes pre- I of the rustinhibitor obtained in Example 2 in a refined oil.

The properties of the improved oil compositions of Examples 4 and 5ante, as compared with the properties of the base oil employed, are asfollows:

Improved lubricant Properties Base oii Ex. 4 Ex. 6

Gravity, API Q 2a 2 2s. 1 28.8 Viscosity, SUV. 100 F 102 102 103 Flash,OC, F 330 320 330 Fire, 00, F. 365 360 365 Pour, F... --30 -30 30 Color,Saybolt +7 +5 +5 Carbon residue. Trace 0. 01 0. i Neutralization No NilNil Nil These improved oils had'excellent lubricatin properties. Theyalso effectively protected steel and other metals against rusting andcorrosion.

In fact, the improved oil compositions of Examples 4 and 5, when testedfor non-rusting prop erties by the various accelerated corrosion testsdescribed post, gave excellent results as compared with the base oil.For instance, in special corrosion test No. 1, the base oil began toshow rust on a steel strip after six hours in the test, whereas aftertwelve days the improved oil showed no evidence of rust. In the otherand more drastic corrosion tests described post, these improved oilsshowed even greater superiority over the base oil as regards protectingsteel and other metals against tarnish and corrosion. The results ofthese special corrosion tests are summarized in the following table.

The special corrosion tests referred to in the above table were asfollows:

Test No. 1.-36 cc. of the oil or oil composition to be tested and 4 cc.of. distilled water are put in a 1" by 6" Pyrex test tube and a polishedstrip of copper or steel is immersed in the liquids. To mix the oil andwater, 2000 cc. of air per hour are bubbled through the mixture from apoint within the bottom of the test tube. The apparatus is set in awater bath maintained at 122 F. (50 C.) and the original water level inthe tube is maintained by additions of fresh water over 24 hours. Thetest is continued for twelve days regardless of Whether or not the metalstrip showed signs of corrosion, This test may also be carried out withother metal strips such as zinc and tin as well as with copper or steelstrips.

In this test, the lower part of the metal strip' is completely immersedin the water and the only 76 names way the oil can wet the metal surfaceis for the oil to creep down over it against the water pressure.Accordingly, rusting immediately begins at the level where the oil andthe water meet, unless the metal surface is preferentially wetted by theoil; that is, unless the oil film is capable of spreading on the metalsurface and displacing water therefrom.

In other words, this test is a rather drastic one for the protectiveproperties of oils and oil compositions as regards the prevention ofrust, tarnish and corrosion. For instance, in this test, ordinarily asteel strip shows rust in about 6 hours and a copper strip will tarnishwithin approximately 12 hours when an uninhibited oil is so tested. Onthe other hand, generally the addition of as little as 0.1 per cent byweight of our rust inhibitors to the oil will maintain both copper andsteel strips free from tarnish and rust for periods up to 12 days, amaximum duration of this test.

Test No. 2.In this test, cc. of the oil or oil composition to be testedand 20 cc. of distilled water are placed in a 400 cc. beaker, and apolished metal strip is immersed in the oil-water mixture; 2000 cc. ofhumidified air per hour were passed through the mixture and the apparatuis maintained at 122 F. as in Test 1. The water level is maintained bydaily additions of distilled water and at the end of 12 days the waterlayer is removed by syphon and fresh water is added. The water removedis analyzed to determine whether the inhibitor is being extracted orleached from 'the oil solution. Fresh strips are added when the water ischanged, so as to present a fresh metal surface to the partially leachedoil. This cycle is continued for '72 days unless the test specimenbecomes too corroded, making further testing impractical. In this test,the test specimens are usually steel, copper, tin, silver and zinc,although other special metals may be used.

Test N0. 3.-The apparatus outlined in Test 1 is employed and the testingconditions are identical, except that water containing sodium chloridein the concentration equivalent to that of the total salt content of seawater is added instead of distilled water. This is a much more severetest and is conducted also for 12 days, the water level being maintainedin the same manner as for Test 1.

In general, the special corrosion tests described ante are drastic testsof the rust preventive properties of oil compositions. In these tests,the strip of steel or other metal is subiectedto attack by moisture andair under extremely severe conditions particularly in Test N0. 3.Further, the oil film on the metal and the oil itself are exposed to notonly the leaching action of the water but also to oxidation.Accordingly, if rusting is prevented under such drastic conditions inthese tests, there is good assurance that the inhibitor will be capableof preventing, or at least retarding rusting even under extremely severeservice conditions. Therefore, an inhibitor which, when dissolved in anoil, permits the oil to pass all three of these tests is considered anexcellent inhibitor..

As shown ante, improved oil compositions containing our rust inhibitorshave successfully passed all of these tests. Further, our improved oilcomposition in addition to having excellent anti-rust properties arealso excellent lubricants. Likewise, as shown ante, the anti-rustproperties of the improved oil may be controlled by selecting the rustinhibitor and varying the proportions thereof incorporated in the oil.For instance, in

certain special cases, where the prevailing conditions are so extreme asto require the lubricant to be extremely highly protective toward metalsurfaces, at higher percentage of rust inhibitor is incorporated in theoil. The following example is illustrative of such embodiments of thisinvention.

Example 6.-'In preparing one such lubricant, 0.3 per cent by weight ofthe rust inhibitor obtained in Example 1 was incorporated in a suitableoil base. The oil base selected and the improved lubricant made from ithave the following properties:

Base oil Improved oil Gravity, "API. 2s. 5' 2s. 4 Viscosity, SUV, 100 F110 109 Color, N PA 1.25 i. 25

This improved oil is capable of preventing rusting and corrosion ofmetals under extreme conditions, even in the presence of salt and saltwater. For'instance, when tested by the special corrosion Tests Nos. 1and 3 ante, the improved oil showed no evidence of corroding eithercopper or steel after 12 days in either of the above tests. 0n the otherhand, the base oil allowed the steel strip to rust in approximately 8hours in the fresh water (Test N o. 1) and in about 3 hours in the saltwater test (Test No. 3) Also, with the base oil, the copper strips werecoated Witha greenish deposit after overnight testing; the copper stripsbeing more slowly attacked than the steel strips but never-.

theless substantially tarnished and corroded.

The specific embodiments described above are merely illustrative of thepractice of this invention and other embodiments thereof may be used asdesired; for instance, these rust inhibitors are compatible with variousother compounding in gredients and they may be added to blended oilbases or compounded lubricants to obtain other types of improvedlubricants. Improved oil compositions can be prepared from base oilscontaining varying amounts of fatty oils admixed with mineral oil, suchblends being especially useful as household lubricants. B the presentinvention, any of the previously known household or other lubricantscontaining relatively light lubricating oils can be improved by addingsmall amounts of our rust inhibitors as described.

The invention i equally applicable to heavy mineral oils, petrolatumoils, greases, and jellies;

presents a more economical remedy for these conditions, for corrosion iseffectively retarded under such conditions when from 0.5 to 1.0 percent'by weight of our compounds is added to a motor oil. Adding thehighly potent rust preventive compound during the latter part of thebreak-in period for the new engine, with operation for sumcient timeafter addition to assure full mixing and coating of parts, will preventrusting.

Extensiv tests in which the pH values of the agent of the presentinvention as employed in finished oils were varied, confirm ourdiscovery thatthe optimum result for a given amount of the agent in oilare secured when the pH value is maintained within the stated range of5.5 to 7.5 for the compounding agent. There is usually a slight drop inpH value in the dilute finished oil solution as compared with thevaluesfor the compounding agents or mixtures thereof. The finished'oil (whichusually contains only a small proportion of the dilute compoundingagent) should test between 5.0 and 6.0; advantageously around 5.7.

Any substantial departure from the stated range either on the alkalineor acid side gives less desirable results. For example, with an undulylow pH value (acid side) there is some rusting of steel surfaces by oursteel strip corrosion test, while compositions with an excessively highpH value (alkaline side) may produce greenish corrosion efiect in thecorrosion tests with copper surfaces and the like, although not affectinsteel to any appreciable extent. The exact adjustment is attained inpreparing the rust inhibitor compound by reacting the desired molecularproportions of the two agents in the manner described. and after theneutralization or compounding reaction has progressed pract cally tocompletion, by testing the reaction product, and making any minoradjustments that are necessary for exact control by adding the requiredsmall additional proportion of the amines (if on the acid side, of ourdesired range) or of the acid phosphate ester (if the alkaline side). Inmeasuring the pH of the anti-rust agents of the present invention andoils containing them, which are both substantially water-insoluble, thesample is dissolved in normal butanol (whichcontain a small amount ofwater) adjusted exactly to pH 7.0. The butanol acts as a blending agentfor the water and the relatively insoluble material, but

in fact to any petroleum lubricant or coating oil,

in which corrosion-preventive properties are desired. In the claims theterm petroleum lubricant includes mineral oils, jellies and the likeeven when used for purposes other than strict lubrication, e. g.slushing'oils and gun greases.

One important application of the present invention is the prevention ofrusting in automotive and aviationengines before or after these havedoes not appreciably alter the pH value as it is of R O l-O n wherein Rrepresents a tertiary butyl group and R and R" represent an alkyl groupselected from the clas consisting of methyl, secondary butyl andtertiary butyl groups, said substantially neuformula I I tral additionproducts having a pH between 5.5'

' neutral addition product of said acid phosphate di-ester anddodecylamine. I

4. The improved oil composition of claiml wherein saidaddition productis a substantially neutral addition product of saidvprimary fatty aminesand di-i2,4,6+trl-tertiary-butyi-phenyl) phosphate.

'5. The improved oil composition oi! claim 1 tri-alkylated phenolshaving the following tor--v mula I wherein it represents a tertiarybutyl group and R and R" represent an alkyl group selected from theclass consisting oi methyl, secondary butyl and tertiary butyl groups,said substantially neutral additionproducts having a pH between 5.5

, and 7.5 and the proportion thereoi'dissolved in the lubricant beingsufllcient to prevent rusting of ferrous metals. 8. The improved oilwherein said mineral lubricating oil is a light wherein said additionproduct is a substantially neutral addition product of dodecylamine anddi-l2,4,6-tri-tertiary-butyl-phenyl) phosphate,

said addition product having a pH value of 7.2;

6. The improved oil composition of claim 1 wherein saidpetroleumiubricant contains from 1 0.01 to 10.0 per cent by weight ofsaid substan-' tially neutral addition product dissolved therein.

v 7. Asimproved oil compositions, effective as a lubricant for ierrousandother metal surfaces and capable of preventing corrosion thereof inthe presence'oi moisture and air, the improl 2d oil compositionscomprising a mineral lubricating oil and 0.01 to 10.0 per cent by weighton the oil of a substantially neutral addition product or primary Iattyamines containing iron'rB t0'18 carbon atoms and acid phosphatedi-estersoi mineral oil having a Saybolt Universal viscosity between and150 seconds at F. I I I v 9. The improved oil composition of claim 7wherein the'addition product is a substantially neutral a'dditionproductoi dodecylamine and i di-(2,4,6 -tri-tertiary-butyl phenyl) phosphate Ia lubricant for ferrous and other metal surfaces and capable ofpreventing corrosion thereof in thepresence of, moisture and air, theimproved 10.'As improved oil compositions, effective as oil compositioncomprising a light mineral oil of viscosity between 60 and seconds SUVat 100 F. containingbetween 0.01 and 10.0 per cent of a substantiallyneutral addition product of dodecylamine anddi-(2,4,6-tri-tertiary-butylphenyl) phosphate, said addition producthaving a pH value of 7.2 and the proportion thereof bev ing sufficientto prevent rusting of ferrous metals I v HERSCHCEL G. SMITH.

v I TROY L. CANTREIL.

composition of I claim

